As the Internet evolves into a worldwide commercial data network for electronic commerce and managed public data services, increasingly, customer demands focus on the need for advanced Internet Protocol (IP) services to enhance content hosting, broadcast video and application outsourcing. To remain competitive, network operators and Internet service providers (ISPs) must resolve two main issues: meeting continually increasing backbone traffic demands and providing a suitable Quality of Service (QoS) for that traffic. Currently, many ISPs have implemented various virtual path techniques to meet the new challenges. Generally, the existing virtual path techniques require a collection of physical overlay networks and equipment. The most common existing virtual path techniques are: optical transport, asynchronous transfer mode (ATM)/frame relay (FR) switched layer, and narrowband Internet protocol virtual private networks (IP VPN). FIG. 1 schematically illustrates the common existing virtual path switched layers.
The optical transport technique 102 is the most widely used virtual path technique. Under this technique, an ISP uses point-to-point broadband bit pipes to custom design a point-to-point circuit or network per customer. Thus, this technique requires the ISP to create a new circuit or network whenever a new customer is added. Once a circuit or network for a customer is created, the available bandwidth for that circuit or network remains static. The ATM/FR switched layer technique 104 provides QoS and traffic engineering via point-to-point virtual circuits. Thus, this technique does not require the creation of dedicated physical circuits or networks, as is the case with the optical transport technique 102. Although this technique 104 is an improvement over the optical transport technique 102, this technique 104 has several drawbacks. One major drawback of the ATM/FR technique 104 is that this type of network is not scalable. In addition, the ATM/FR technique 104 also requires that a virtual circuit be established every time a request to send data is received from a customer.
The narrowband IP VPN technique 106 uses best effort delivery and encrypted tunnels to provide secured paths to the customers. One major drawback of a best effort delivery is the lack of guarantees that a packet will be delivered at all. Thus, this is not a good candidate when transmitting critical data.